A.c. impedance study on the interfacial properties of passivated Ti13Zr13Nb alloy in physiological saline solution

摘要

In this work, the Ti13Zr13Nb shape memory alloy that was naturally passivated in air has been studied towards long-term corrosion performance in the physiological saline solution. The electronic impedance spectroscopy method was used to detailed study on the electrolyte|passive layer interfacial properties. The equivalent electrical circuit for the pitting corrosion was applied, and the discussion on the electrolyte|electrode interfacial properties was realized with respect to the physical meaning of the used circuit elements. The study shows that the Ti13Zr13Nb alloy is characterized by high corrosion resistance. ESI measurements revealed the formation of a protective oxide film on the Ti13Zr13Nb surface, during 20 days of exposure in 0.9% NaCl solution at 37℃. In the early days of immersion, there was a slight decrease in corrosion resistance, which in the next 15 days remained unchanged, indicating very good protective properties of the formed oxide film. Performed research indicates that the Ti13Zr13Nb alloy is promising biomaterial to medical applications.